setResponderAndExtractTransfer() — react Function Reference

Source Code

packages/react-native-renderer/src/legacy-events/ResponderEventPlugin.js lines 536–635

function setResponderAndExtractTransfer(
  topLevelType,
  targetInst,
  nativeEvent,
  nativeEventTarget,
) {
  const shouldSetEventType = isStartish(topLevelType)
    ? eventTypes.startShouldSetResponder
    : isMoveish(topLevelType)
      ? eventTypes.moveShouldSetResponder
      : topLevelType === TOP_SELECTION_CHANGE
        ? eventTypes.selectionChangeShouldSetResponder
        : eventTypes.scrollShouldSetResponder;

  // TODO: stop one short of the current responder.
  const bubbleShouldSetFrom = !responderInst
    ? targetInst
    : getLowestCommonAncestor(responderInst, targetInst);

  // When capturing/bubbling the "shouldSet" event, we want to skip the target
  // (deepest ID) if it happens to be the current responder. The reasoning:
  // It's strange to get an `onMoveShouldSetResponder` when you're *already*
  // the responder.
  const skipOverBubbleShouldSetFrom = bubbleShouldSetFrom === responderInst;
  const shouldSetEvent = ResponderSyntheticEvent.getPooled(
    shouldSetEventType,
    bubbleShouldSetFrom,
    nativeEvent,
    nativeEventTarget,
  );
  shouldSetEvent.touchHistory = ResponderTouchHistoryStore.touchHistory;
  if (skipOverBubbleShouldSetFrom) {
    accumulateTwoPhaseDispatchesSkipTarget(shouldSetEvent);
  } else {
    accumulateTwoPhaseDispatches(shouldSetEvent);
  }
  const wantsResponderInst = executeDispatchesInOrderStopAtTrue(shouldSetEvent);
  if (!shouldSetEvent.isPersistent()) {
    shouldSetEvent.constructor.release(shouldSetEvent);
  }

  if (!wantsResponderInst || wantsResponderInst === responderInst) {
    return null;
  }
  let extracted;
  const grantEvent = ResponderSyntheticEvent.getPooled(
    eventTypes.responderGrant,
    wantsResponderInst,
    nativeEvent,
    nativeEventTarget,
  );
  grantEvent.touchHistory = ResponderTouchHistoryStore.touchHistory;

  accumulateDirectDispatches(grantEvent);
  const blockHostResponder = executeDirectDispatch(grantEvent) === true;
  if (responderInst) {
    const terminationRequestEvent = ResponderSyntheticEvent.getPooled(
      eventTypes.responderTerminationRequest,
      responderInst,
      nativeEvent,
      nativeEventTarget,
    );
    terminationRequestEvent.touchHistory =
      ResponderTouchHistoryStore.touchHistory;
    accumulateDirectDispatches(terminationRequestEvent);
    const shouldSwitch =
      !hasDispatches(terminationRequestEvent) ||
      executeDirectDispatch(terminationRequestEvent);
    if (!terminationRequestEvent.isPersistent()) {
      terminationRequestEvent.constructor.release(terminationRequestEvent);
    }

    if (shouldSwitch) {
      const terminateEvent = ResponderSyntheticEvent.getPooled(
        eventTypes.responderTerminate,
        responderInst,
        nativeEvent,
        nativeEventTarget,
      );
      terminateEvent.touchHistory = ResponderTouchHistoryStore.touchHistory;
      accumulateDirectDispatches(terminateEvent);